Triple valve for air-brakes.



PATENTED JULY 18, 1905.

0. A. ALEXANDER.

TRIPLE VALVE POR AIB, BRAKES.

APPLICATION FILED AYE. 23,1904.

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Alfomey Anuntw 5. MANA co.. mwammlns. WASNINGYIJN, uA c UNITED STATES Patented July 18, 1905.

PATENT OFFICE.

TRIPLE VALVE FOR AIR-BRAKES..

` SPECIFICATION forming part of Letters Patent No. 794,835, dated July 18 1905,

Application filed April 23, 1904. Serial No. 204,556.

\ for Air-Brakes, of which the following is a full, clear, and exact description.

This invention has for its object to produce a simple single-element triple valve for airbrake apparatus, whereby both service and emergency stops may be readily elected without the use oi" slide-valves and special emergency valves or pistons.

The invention consists of a suitably-ported valve-shell adapted to be connected to the auxiliary reservoir and train pipe and having a single piston provided with ported laps cooperating with the ports in the shell, so as to actuate the brake-cylinder to apply the brakes in both service and emergency stops and to release them, and serving thus without the interposition of other valves, pistons, or equivalent valve-like mediums between it and the engineers valve.

In the accompanying drawings, illustrating the invention, in the several figures of which like parts are similarly designated, Figure 1 is a view, partly in section and partly in elevation, showing the valve applied to a standard freight-car air-brake apparatus. Fig. 2 is a longitudinal section of the triple valve. Fig. 3 is an elevation of the gasket. Fig. 4 is a bottom plan View of the piston. Fig. 5 is an elevation of the retaining-ring.

The brake cylinder 1, with its springpressed piston 2, and the auxiliary reservoir 3, with its through-pipe 4 for connecting the triple valve and the brake-cylinder, may be and are here shown as usual.

The triple valve comprises ashell 5, having a train-pipe connection 6 and flange 7 by which it may be bolted to the auxiliary reservoir. In the train-pipe connection is a seat 8, and in the retaining-ring 9 at the opposite end is a seat 10 for receiving and guiding the stems 11 and 12 of the piston 18. This retaining-ring maintains constant communication between the triple valve and the auxiliary reservoir. An expansion-spring 14 is interposed between seat 8 and the piston. The shell 5 has a bushing 15, in which is cut a leakage-groove 16 next the piston at the point where said piston comes to rest in exhausting the brake-cylinder, so that the trainpipe air may leak past the piston int-o and fill the auxiliary reservoir, as usual. The piston is made with laps 17 and 18 at front and rear, the former provided with one or more throughports 19 and the latter provided with an inclosed port 20, made as a recess in its periphery.

21 is a port in the shell, leading from the brake-cylinder to the front of the piston, and 22 is a port in the shell opening into port 21 and into the shell in rear of the piston.

23 is the exhaust-port, opening into the external atmosphere.

Ports 19 and 21 cooperate, and ports 20, 22, and 23 cooperate.

The triple valve has a leather or other gasket 24 interposed between it and the auxiliary reservoir.

The triple valve is shown in Fig. 2 as in the normal position, train running and air leaking past its piston into the auxiliary reservoir. It' the train-pipe pressure be reduced, the piston will be moved to the right, closing the leakage-port and uncovering port 22, so as to permit the air to flow from the auxiliary reservoir through the valve-shell and thence through port 22 into the through-pipe 4, leadv ing from said valve into the brake-cylinder, thereby applying the brakes in accordance with ordinary service -stop usage. If an emergency-stop be required, then the trainpipe pressure is Jfurther reduced, and the piston will be moved still farther to the right until its port 19 registers with the port 21, thereby admitting train-pipe pressure also into the air-brake cylinder, in addition to the pressure from the auxiliary reservoir. After an emergency application has been made the spring 14 will move the piston into lap position. Upon restoration of full train-pipe pressure its force, aided by the spring 14, Will suilce to move the piston to the left against the auxiliary-reservoir pressure, close ports 21 and 22, and open communication between the brake-cylinder `and the exhaust, and so cause the release of the brakes.

It will be seen that this piston-valve performs the functions and takes the place of the piston and `slide valve of the plain triple and also of the emergency piston of the quick-action valve.

What I claim isN A triple valve, comprising a shell adapted to be connected with an auxiliary reservoir in open communication therewith, and a piston in said'shell exposed on one side to train-pipe pressure and on the other side to auxiliaryreservoir pressure, and having front and rear laps on one side only, the front lap having a through-port and the rear lap having an inclosed port, the shell having a front port leading rearwardly to the brake-cylinder and controlled by the through-port lap, and a rear portl leading into the front port and an exhaust-port, the rear port and exhaust-port controlled by the inclosed-port lap, so that upon reduction of train-pipe pressure the pisauxiliary-reservoir and train-pipe pressure,

thereby effecting respectively service and emergency stops without the intervention of auxiliary or supplementary valves.

In testimony whereotl I have hereunto set my hand this 20th day of April, A. D. 1904.

OLIVER A. ALEXANDER.

Witnesses:

R. B. CHASE, K. E. FITZGERALD. 

